Collapsible ladder



June 24, 1969 v, L, NEAL 3,451,506

COLLAPSIBLE LADDER Filed om. 15, 1967 Sheet 1 of 2 ll In I /9 INVENTOR vzmvolv 1. New.

Filed Oct. 13, 1967 INVENTOR V'R/Vd/V 1. Meal.

BY Z/ -UO. my

ATTORNEY United States Patent US. Cl. 182-195 4 Claims ABSTRACT OF THE DISCLOSURE A collapsible ladder characterized by a series of rung sections, nestable within each other when collapsed and maintained in extended position by load supporting spring clip members.

The need for a reliable, light-weight ladder which, when non-extended, can be stored in a small space, such as the trunk of an automobile, is increasingly evident. The invention satisfies the aforesaid purpose, being a ladder which can be extended into any desired length, but which, at the same time, is made up of sections which can nest, one into the next, to a minimal space requirement when in a collapsed condition.

Briefly, the ladder comprises a series of rung sections, such rung sections being defined by hollow side members and an interconnecting cross rung. The width of each section, from lowermost to uppermost, decreases in size, so that each higher section is received within the hollow side members of the section adjacent and below.

Collapsing of the ladder sections is simply accomplished through the use of spring clips, disposed on the inside surface of each side member. Such spring clips each serve a dual purpose, namely, to automatically position and support the respective sections of the ladder in use, and, when squeezed outwardly, to permit the nesting of the respective sections one with respect to another.

The uppermost section of the collapsible ladder has bumpers or similar mar preventing members at the free upper ends of the side members, while the lowermost section, at the free lower ends of the side members, adjacent the supporting surface, include conventional feet to prevent any skidding of the ladder during use.

A better understanding of the invention will become more apparent from the following description, taken in conjunction with the accompanying drawings, wherein FIG. 1 is a view in vertical section, partly fragmentary, of several sections of the collapsible ladder in an extended position;

FIG. 2 is a view corresponding generally to FIG. 1, but showing the ladder sections in a collapsed or nesting relationship;

FIG. 3 is a view in horizontal section, taken at line 3-3 on FIG. 2 and looking in the direction of the arrows, showing details of the nested ladder sections;

FIG. 4 is an enlarged view showing one approach to securing the spring clip to a ladder section; and,

FIG. 5 is another enlarged view showing a different approach for securing the spring clip to a ladder section.

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now to FIGS. 1, 2 and 3, the collapsible Patented June 24, 1969 ladder 10 of the invention is shown comprising a base or ground supported rung section '12, a first upper rung section 14, and a fragmentary portion of a second upper rung section 16, leading successively to a top section 20. In each instance, although scaled, proportion-wise, differently from bottom to top, each rung section comprises hollow side members 12a and 12b, 14a and 14b, 16a and 16b, and 20a and 20b, respectively, typically made from a light-weight material, such as aluminum, for example. The hollow side members are respectively interconnected by cross rungs 12c, 14c, 16c and 200, where, conventionally, the foot receiving portion of each is enlarged and includes a roughened (not shown) foot receiving surface.

As is evident from FIGS. 1 and 2, the lower ends of the side members 12a and 12b of the bottom rung section 12 have enlarged anti-slipping feet 19, while the upper ends of the side members 20a and 20b of the top rung section 20 have steadying bumpers 24, as in conventional practice.

With particular reference to FIG. 3, it will be noted that each side member 12a, 14a, and 16a, although reversed for opposite side members, has a characteristic configuration in cross section, i.e. an inwardly jutting or extending portion towards the center of the ladder. More specifically, and looking at side member 14a in FIG. 3, the makeup thereof comprises an outer surface 14d, a front (to the viewer) surface 146, a rear (to the viewer) surface 14], edge surfaces 14g and 14h facing towards the center of the ladder rung section, and the aforesaid jutting portion 141'. Such a relationship affords ladder stability, considering that no forward or backward movement nor any lateral movement can result between the respective ladder rung sections. Actually, the only spacing requirement between respective ladder rung sections is that which permits the desired sliding and nesting relationship.

With further reference to FIGS. 1, 2 and 3, and particularly FIG. 3, spacing is provided between each of the jutting portions of the ladder rung sections 12, 14 and 16, such space permitting the utilization of a spring clip 25, preferably made from spring steel, for example. As particularly evident from FIGS. 1 and 2, each spring clip 25, assumes at least two positions, i.e. one of assembly, which includes assuming the load between respective ladder rung sections, as in FIG. 1, and, when pressed outwardly, one which permits a nesting relationship between adjacent rung sections because of the provided spacing between the jutting portions which receives the compressed spring clips 25, as in FIG. 2.

With reference now to FIGS. 4 and 5, each spring clip 25 may be secured to a side member 14a in various manners, two being representatively shown. FIG. 4 shows the spring clip 25 directly secured to the inner surface of the jutting portion 14i of a side member 14a through pivoting action. On the other hand, FIG. 5 shows a band 27 which encircles the outer surfaces of the side member 14a of a rung section 14, being positioned by pivoting, for example, but securing the spring clip 25 between the band 27 and a surface of the side member 14a.

In any event, and in use, the side members 12a and 12b of the base rung section 12 each receive the side members 14a and 14b, respectively, of the first upper rung section 14. Similarly, the latter each receive, respectively, the side members 16a and 16b of the second upper rung section 16. The preceding continues for the desired length of the collapsible ladder.

As should be evident from FIG. 1, the spring clips 25 readily move into load assuming position upon extension of the respective ladder rung sections from the nested position of FIG. 2. Conversely, when it is desired to collapse the ladder, and as stated above, the spring clips 25 are each squeezed outwardly, and are moved into the spacing provided between each of the jutting portions of the various ladder rung sections.

In other words, through the use of the spring clips, the ladder is readily and simply moved from its extended to its non-extended positions, and conversely. The invention provides a very compact relationship of the rung sections when the ladder is collapsed, looking for ready transporting, as in the trunk of an automobile. In that the ladder is typically made from aluminum, or like lightweight material, the ladder, either extended or non-extended, is readily carried and positioned.

The collapsible ladder described above is, of course, susceptible to various changes within the spirit of the invention. For example, the spring clips 25 may be secured to the side members in other manners than those described herein. Moreover, proportioning of the ladder may be varied. Thus, the above description should be considered illustrative and not as limiting the scope of the following claims.

I claim:

1. A collapsible ladder comprising a plurality of rung sections, each rung section defined by hollow side members and an interconnecting rung member, said hollow side members defined in cross-section by a front surface, a side surface, a rear surface, and side edge surfaces having a jutting portion therebetween, and spring clip members 4 disposed on said rung sections selectively permitting the extending and the collapsing of successive rung sections, said jutting portions of said hollow side members defining a space therebetween adapted to receive said spring clip members in a nested position of one rung section with respect to another rung section.

2. The collapsible ladder of claim 1 Where said rung sections are in nesting relationship one with respect to another.

3. The collapsible ladder of claim 1 Where said rung sections decrease in width from the bottom to the top of the ladder.

4. The collapsible ladder of claim 1 where said spring clip members bear the load between successive rung sections when extended.

References Cited UNITED STATES PATENTS 667,927 2/ 1901 Weeks l82209 1,712,942 5/1929 Smith .1 82-495 2,542,398 2/ 1951 'Crumpton 182209 2,993,561 7/ 1961 Watson 182195 REINALDO P. MACHADO, Primary Examiner.

US. Cl. X.R. 182207 

